IRS letter claiming taxes due on 1099-Q

[amptax]

I received a letter from the IRS on my 2023 tax return saying I did not claim my 1099-Q withdrawal (issued to me, but for my son) income and that I owe taxed on it as well as removed the $2500 child tax credit.  I entered my 1099-Q info as well as my 1098-T info and other college expenses supporting the 529 withdrawal as non-taxable.  Turbotax walked me through adjustments to my education expenses to allow the credit if I recall correctly.  I looked at my 1040 and the 1099-Q info gets recorded on schedule 1, line 8z.  However the 1099-Q worksheet does not get filed.  Error check was clean when I filed and I have followed this process for the prior 3 years of his college education.  Any idea why the IRS called this out?  Is there issues or missing documents Turbotax did not send? 

[AmyC]

No, they randomly audit returns and ask for supporting information. I went through this as well. Just send them all your tuition expenses, room and board, whatever the Q went towards. Write a simple letter. The IRS has a document upload available as well. You can contact the department that sent the letter if they didn't include the portal information.

For example:

Q income of $xxx

Room and board $yyy

Tuition $zzz

and so on

Leaves no taxable amount according to IRS Pub 970.

Enclosed are the expenses to back up the distribution. 

I do qualify for the AOTC because:

list Qualified Education Expenses - Internal Revenue Service

Enclosed are the expenses to back up the credit.

[amptax]

Would be the case if they did not ask for supporting backup proving that is was withdrawn for education expenses?  They said it was unreported income.  I sent them 1099-Q form from Turbotax showing the calculations as well as the 1098-T showing my son was a student that year.  But not other receipts